common-testing-conventions

Structure each test with exactly one Arrange, Act, and Assert comment block. Arrange sets up data and mocks, Act performs a single invocation on the subject under test, and Assert contains all verifications. Never mix phases or add conditionals inside blocks.

Use the Should_{ExpectedBehavior}_When_{Condition} pattern in PascalCase, such as Should_CreateGroup_When_RequestIsValid. Avoid natural language sentences, vague names like Should_Work, or prefixes like TestCreateGroup.

In C# use AwesomeAssertions with action.Should().ThrowAsync<T>(), in Python use a lambda with pytest.raises(), and in Vitest use expect(...).rejects.toThrow(). The exception assertion always lives in the Assert phase, never in try/catch inside the test.

No, try/catch/finally and control flow are prohibited inside test bodies. Use framework teardown instead: IAsyncLifetime or IDisposable in xUnit, yield fixtures in pytest, and beforeEach/afterEach hooks in Vitest.

Only as a narrow diagnostic exception when production-behavior tests or a direct workflow reproduction cannot localize the failure. The focused test must target the smallest stable contract and state why consumer evidence is insufficient; it is never added for coverage.

.NET uses NSubstitute with Received/DidNotReceive verification, TypeScript uses Vitest's vi.fn() and module mocks, and Python uses unittest.mock Mock and AsyncMock. All stacks require verifying mock interactions in the Assert phase.